OMAHA, Neb. — Police called in May to an Omaha home where a prominent pathology doctor and his wife had been killed noted striking similarities between the stab wounds on the right side of the victims' necks and those inflicted on an 11-year-old boy and a housekeeper slain five years earlier.

That parity was detailed in an arrest affidavit unsealed Thursday in the case of Dr. Anthony Garcia, who is charged with four counts of first-degree murder and weapons counts in the May deaths, as well as the slayings in 2008.

Police soon discovered it wasn't just the stab wounds that linked the victims.

The slain doctor, Roger Brumback, was the chairman of the Creighton University School of Medicine's pathology department. The boy stabbed to death five years earlier in a nearby neighborhood was the son of a professor who worked closely with Brumback in the same department. That connection led police to research those associated with the department, uncovering another eye-opener — that Hunter and Brumback had fired Garcia from the pathology residence program for "unprofessional conduct" in 2001.

The affidavit was used to support a Nebraska warrant for Garcia, who was arrested Monday in southern Illinois. Nebraska prosecutors say Garcia shot and stabbed Brumback and fatally stabbed Brumback's wife, Mary. Garcia is also charged in the stabbing deaths of 11-year-old Thomas Hunter and his family's housekeeper, Shirlee Sherman.

According to documents that Brumback sent to Indiana medical licensing officials in January, Garcia was fired for trying to sabotage another Creighton resident's efforts to complete his residency. The documents say Garcia called the colleague's wife to needlessly demand that her husband return to the university's pathology department. The wife then tried to contact her husband, who was taking a high-stakes test for his residency at the time.

Documents to and from various medical schools and state medical licensing agencies show that Garcia also left a New York residency program in 1999 to avoid disciplinary action, and that his application for medical licenses in various states were rejected following his firing from Creighton. Police have cited those troubles as a likely motive for the killings.

Garcia's attorneys said Wednesday that Garcia, who awaits extradition from Illinois, denies the charges.

Nebraska prosecutors are weighing whether to seek the death penalty against Garcia. Regardless, a conviction of first-degree murder in Nebraska brings a minimum sentence of life in prison without parole.

The Nebraska prosecutor, Douglas County Attorney Don Kleine, said Wednesday that he expected Garcia to be returned to Omaha by Friday and that he would likely be arraigned Monday or Tuesday.

Kleine did not return messages seeking comment Thursday. Officials at southern Illinois' Jackson County Jail could not say when Nebraska officials would accompany the doctor back to Omaha.

The affidavit says the killer used knives found at the homes in the attacks and that the weapons were left behind to be found by police.

Parts of a gun used to shoot Roger Brumback also were found inside his home. The affidavit says the parts were matched to a Smith & Wesson SD9 handgun that police say Garcia bought in March from a gun retailer in Terre Haute, Ind., where Garcia has been living.

Garcia made credit card purchases and a cellphone call in Iowa, about an hour away from Omaha, on May 12, the day the Brumbacks were killed, the affidavit said. Omaha police released a photo of a man who looks like Garcia, taken that day inside a convenience store in Council Bluffs, Iowa, which lies across the Missouri River from Omaha.